In parent application Ser. No. 09/468,427, there is disclosed a system and method for dewatering and treating waste-activated sludge (WAS) emanating from municipal waste, or pulp-waste from a paper mill, as well as treating animal and plant waste. In that application, the method for breaking down the WAS is to subject the WAS to electroporation, which incorporates nonarcing, cyclical high voltages in the range of between 15 kV/cm and 100 kV/cm, which break down inter-cellular and intracellular molecular bonds, to thus release inter-cellular and intracellular water, whereby the WAS is rendered inactive and greatly reduced in mass.
In said above-noted copending application, the apparatus and method disclosed therein, while capable in certain circumstances of being a primary municipal-sludge treatment, its intended and main objective was to use it as a secondary treatment to previously-dewatered municipal waste sludge. It is the goal of the present invention to adapt the method and apparatus of said copending application Ser. No. 09/468,427 into a main, primary treatment of municipal waste sludge.
In a previous (Phase I) project, it has been demonstrated the laboratory feasibility of pulsed electric field (PEF) for disrupting the biomass in waste activated sludge (WAS) derived from municipal wastewater treatment. While there was no significant increase in the solids content of dewatered sludge, the quantity of WAS needing disposal was estimated to be significantly reduced.
Encouraged by the Phase I results, a pilot plant for testing at one or two wastewater treatment plants that generate WAS has been developed. It has been decided that a pulsed electric field (PEF) system that could handle 0.5 to 1.0 pgm WAS feed be designed. This requires an 8 kw power supply capable of generating 30 kV and pulse generator capable of handling 50 amp peak, current, bi-polar pulses, square wave, 10 xcexcs pulse width, and 3000 pulses/second (pps).
It is the primary objective of the present invention to provide a method and apparatus for dewatering municipal waste sludge, paper-pulp waste sludge, animal and plant waste, using electroporation for the primary treatment of the sludge.
It is also a primary objective of the present to provide such a system that will allow flexibility as to the primary and secondary treatment of municipal sludge, paper-pulp sludge, animal and plant waste, whereby the treatment thereof via electroporation may be used either as the primary dewatering treatment, secondary dewatering treatment, direct WAS-treatment, and combinations with other conventional dewatering techniques, in order to provide the municipal treatment plant, or the paper-pulp treatment plant, with the most cost-effective and efficient system as possible.